CHICAGO, April 22 -- What to put down here? He could put down the fastball sign, Brian Schneider figures, and his pitcher will pump it right into the mitt -- this is Johan Santana we're talking about -- right in the sweet spot where the webbing hits the padding, 93 mph strong, in a spot no batter can get to with any authority. Or maybe the slider. Yeah, the slider. With a right-handed batter up, Santana, a lefty, could start it out over the plate, but before the batter realizes it's not the fastball he thinks it is, his bat is whiffing through the zone and the slider is about to hit him on the top of his back foot.

This is the conversation, almost a game, that goes on in Schneider's head anytime he catches Santana, the New York Mets' $137.5 million ace and the consensus best pitcher on the planet -- as he is expected to do Wednesday night at Nationals Park, in the Mets' first visit to Washington this season and Schneider's first time back since the Nationals traded him last November.

But back to Schneider's internal conversation. Of course, there's always the change-up, perhaps the single most diabolical pitch in any pitcher's repertoire in baseball. Schneider could call for one of those -- but the other stuff is so good, might as well save the change-up for later.

"What's really cool," Schneider says, delighting in the description, "is how he throws inside to right-handed batters. He'll drop that slider on the guy's back foot, then come back with the best change-up in baseball, down and away. You can see the [batter] go, 'Oh, wait a minute, he has that change-up, too.' "

And what's amazing, Schneider says, is how seldom Santana shakes him off -- no more than a handful of times in any of Santana's first four starts this season, including a seven-inning gem against the Philadelphia Phillies last Friday night. In that game, Schneider called for first-pitch fastballs to the first 13 batters Santana faced, and eight wound up striking out.

Asked about his willingness to throw whatever Schneider calls, Santana shrugs and says: "The guy is good. And he knows, no matter what he calls, I'm going to throw it with a purpose -- to get somebody out."

But Schneider knows the real truth, and he is perfectly willing to admit it: In many cases, it hardly matters what he calls, or what Santana throws. Whatever it is -- the sword, the knife or the gun -- it's going to be deadly.

"I'm not going to say it's easy calling his game," says Schneider, who has missed three straight games with a bruised forearm but expects to play Wednesday night, "but sometimes it's like, 'Flip a coin.' "

Wednesday night's start in Washington will complete Santana's initial journey through the National League East Division, the landscape the Mets expected him to conquer when, in February, they sent four prospects to the Minnesota Twins to acquire him, then -- to get him to waive his no-trade rights -- handed him the biggest contract for a pitcher in baseball history.

Santana, a two-time Cy Young Award winner, beat Florida in Miami on Opening Day, lost at Atlanta despite giving up only one run in seven innings, then -- after making his Shea Stadium debut against the Milwaukee Brewers, another loss in which his exit from the mound drew a smattering of boos from the home crowd -- dominated the Phillies with a 10-strikeout, no-walk effort, briefly putting the Mets in first place in the division.

Santana's record only is 2-2, his ERA a rather pedestrian 3.25 -- and in fact, the mediocre numbers date from last year's all-star break, since which point he is 7-9 with a 3.87 ERA. But Santana says he isn't concerned about the numbers ("All that matters is that I'm healthy," he says), and the Mets say by merely showing up he already has made a difference in pushing the franchise beyond last September's horrendous collapse, in which it blew a seven-game lead over the Phillies with 17 games to play.

"It's rare when you can say one player brings a team to another level, but I think Johan does that," says Mets third baseman David Wright, who has acknowledged the team lacked a certain mental toughness down the stretch in 2007. "He's very similar to when I saw a healthy Pedro [Martínez]. There's a certain intensity or focus they have that I've never seen in anyone else."

Much was made in the New York papers about the pockets of boos that arose out of the stands at the end of Santana's Shea Stadium debut -- in which the Brewers rocked him for three home runs -- but the majority of fans that day were cheering for him, and the ones who booed undoubtedly will join in the cheers the next time Santana puts a seven-inning headlock on some overmatched foe, which, of course, will be very soon and very often.

"If they boo, that's fine," Santana told reporters after that start, seemingly throwing the insult back in the faces of the fans. "That's the history they have from not being so good, I guess."

In New York, especially if you come to town with a big contract, both the fans and reporters feel the need to test you, to see you if can handle the big-stage pressure. Heaven forbid you stumble once -- it will be twice as difficult to pass the test. In Queens, it took Mike Piazza years to win over Mets fans. Center fielder Carlos Beltrán still is trying, three-plus years into his deal.

"The game is the same," Santana says, describing the difference between the Minneapolis and New York media markets. "But the intensity -- [New York] takes it to a different level. It is different. The media, the fans. But you still know that if you take care of what you do on field, it will be fine. . . . You have to make adjustments."

The pitching, in other words, is the least of Santana's worries. To deal with the media onslaught, the Mets have attempted to limit access to him between his starts, although twice during a two-game series in Chicago reporters were able to circumvent official channels and secure interviews by approaching the affable Santana themselves in the clubhouse.

"I'm the same guy I was" in Minnesota, he says. "The same guy who always tries to have fun on the field."

Nothing has changed, indeed. The Santana show merely has moved to a new, bigger venue. The batters all look the same and have the same intentions. And the catcher still has the best job of all, playing his own twisted game -- flipping a coin to decide which particular method of destruction to unleash upon the poor batter.